Prosecution Insights
Last updated: July 27, 2026
Application No. 18/265,341

HETERODIMERIC IGA FC CONSTRUCTS AND METHODS OF USE THEREOF

Final Rejection §112
Filed
Jun 05, 2023
Priority
Dec 03, 2020 — provisional 63/121,180 +2 more
Examiner
MERTZ, PREMA MARIA
Art Unit
1674
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Zymeworks, Inc.
OA Round
2 (Final)
71%
Grant Probability
Favorable
3-4
OA Rounds
0m
Est. Remaining
99%
With Interview

Examiner Intelligence

Grants 71% — above average
71%
Career Allowance Rate
543 granted / 760 resolved
+11.4% vs TC avg
Strong +36% interview lift
Without
With
+35.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
44 currently pending
Career history
786
Total Applications
across all art units

Statute-Specific Performance

§101
1.5%
-38.5% vs TC avg
§103
39.4%
-0.6% vs TC avg
§102
10.3%
-29.7% vs TC avg
§112
37.2%
-2.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 760 resolved cases

Office Action

§112
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Amended claims 1-3, 11, 15, 19, 27, 37, 48-49, (5/29/2026), and previously presented claims 4-10, 12, 16, 18, 20, 22-25, 30-36, 38-45, are pending and under consideration by the Examiner. Claims 13, 17, 21, 26, 28-29, 46-47, have been canceled. 3. Receipt of Applicant's arguments and amendments filed on 5/29/2026 is acknowledged. The following previous rejections and objections are withdrawn in light of applicants amendments filed on 5/29/2026: (i) the rejection, in part, of claims 1-12, 14-16, 18-20, 22-25, 27, 30-45, and 48-49 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph; Applicant's arguments with respect to the above claims have been considered but are moot in view of the new grounds of rejection over claims 1-12, 14-16, 18-20, 22-25, 27, 30-45, and 48-49. Claim Rejections - 35 U.S.C. § 112(b) 5. The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. 5a. Claims 1-12, 14-16, 18-20, 22-25, 27, 30-45, and 48-49 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention. Amended claim 1, lines 5-7, is vague and indefinite because it recites “…wherein the first and second CH3 domain sequences comprise amino acid mutations as compared to the CH3 domain sequence of a parental IgA Fc having a sequence as set forth in any one of SEQ ID NOs: 42, 43, 44 or 45…”, which SEQ ID NOs are 213 amino acids each, however, the amino acid mutations claimed in the first CH3 domain sequence comprise an amino acid substitution at position A6085Y selected from A6085YF, A6085YY, A6085YM, A6085YW and A6085YH, and an amino acid substitution at position T6086 selected from T6086Y, T6086F, T6086M, T6086W and T6086H, and the amino acid mutations in the second CH3 domain sequence comprise an amino acid substitution at position W6081 selected from W6081T, W6081L, W6081A, W6081V and W6081I. Therefore, it is unclear where the recited mutation positions are because they do not correspond to the positions in SEQ ID NOs: 42, 43, 44 or 45. Claim 48 is vague and indefinite for several reasons. Claim 48, lines 5-7, “…wherein the first and second CH3 domain sequences comprise amino acid mutations as compared to the CH3 domain sequence of a parental IgA Fc having a sequence as set forth in any one of SEQ ID NOs: 42, 43, 44 or 45…” which SEQ ID NOs are only 213 amino acids each. However, (a) the amino acid mutations claimed in the first CH3 domain sequence comprise the amino acid substitutions: A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6079V, W6081T and I6088L; or (b) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6007F, L6079V, W6081T and I6088L; or (c) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: H6005Y, A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: H6005Y, L6079V, W6081T and I6088L. Therefore, it is unclear where the recited mutation positions are because they do not correspond to the positions in SEQ ID NOs: 42, 43, 44 or 45. Claim 48, line 22, is vague and indefinite because it recites “about 74°C” and it is unclear if this limitation encompasses 70°C, 75°C, or even 80°C. Similarly, claim 2, lines 2-3, is vague and indefinite because it recites “about 74°C” and it is unclear if this limitation encompasses 70°C, 75°C, or even 80°C. Claim 23, line 3, remains vague and indefinite because it recites the limitation “introduce cysteine residues capable of forming a disulfide bond”, however, it is unclear from the claim where the specific cysteine residues are introduced within a parent polypeptide, since the claim does not provide a parent polypeptide (amino acid sequence of specific SEQ ID NO), and therefore, it is impossible to determine where these cysteine residues would be introduced in the parent polypeptide. Similarly claims 24 and 25 are rejected as vague and indefinite because they recite “introduce cysteine residues”, however, it is unclear from the claim where the specific cysteine residues are introduced within a parent polypeptide, since the claim does not provide a parent polypeptide (amino acid sequence of specific SEQ ID NO). Claim 27, lines 5-7, is vague and indefinite because it recites “…wherein the first and second CH3 domain sequences comprise amino acid mutations as compared to the CH3 domain sequence of a parental IgA Fc having a sequence as set forth in any one of SEQ ID NOs: 42, 43, 44 or 45…” which SEQ ID NOs are only 213 amino acids each. However, (a) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: A6085YY and T6086L, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6079T, W6081L and I6088L; or (b) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: A6085YY and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6079T, W6081L and I6088L; or (c) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6079V, W6081L and I6088L; or (d) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6079V, W6081T and I6088L; or (e) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: T6022V, A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6079V, W6081T and I6088L; or (f) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: T6022L, A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6079V, W6081T and I6088L; or (g) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: T6022I, A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6079V, W6081T and I6088L; or (h) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: L6007F, L6079V, W6081T and I6088L; or (i) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: H6005Y, A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: H6005Y, L6079V, W6081T and I6088L; or (j) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: H6005C, A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: P6010C, L6079V, W6081T and I6088L; or (k) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: P6010C, A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: H6005C, L6079V, W6081T and I6088L; or (l) the amino acid mutations in the first CH3 domain sequence comprise the amino acid substitutions: H6005C, P6010C, A6085YF and T6086Y, and the amino acid mutations in the second CH3 domain sequence comprise the amino acid substitutions: H6005C, P6010C, L6079V, W6081T and I6088L. Therefore, it is unclear where the recited mutation positions are because they do not correspond to the positions in SEQ ID NOs: 42, 43, 44 or 45. Claims 3-12, 14-16, 18-20, 22, 30-45, and 49, are rejected as vague and indefinite insofar as they depend on the above rejected claims for their limitations. Conclusion No claims are allowed. Claims 1-12, 14-16, 18-20, 22-25, 27, 30-45, and 48-49 are rejected. Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Advisory Information Any inquiry concerning this communication or earlier communications from the examiner should be directed to PREMA MARIA MERTZ whose telephone number is (571)272-0876. The examiner can normally be reached on Monday to Thursday from 7:30am to 6:00pm. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, VANESSA FORD, can be reached at telephone number 571-272-0857. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from Patent Center. Status information for published applications may be obtained from Patent Center. Status information for unpublished applications is available through Patent Center for authorized users only. Should you have questions about access to Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) Form at https://www.uspto.gov/patents/uspto-automated- interview-request-air-form. /PREMA M MERTZ/ Primary Examiner, Art Unit 1674
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Prosecution Timeline

Show 2 earlier events
Jan 12, 2026
Examiner Interview (Telephonic)
Mar 02, 2026
Non-Final Rejection mailed — §112
May 29, 2026
Response Filed
Jun 16, 2026
Final Rejection mailed — §112
Jun 17, 2026
Examiner Interview Summary
Jun 17, 2026
Applicant Interview (Telephonic)
Jul 22, 2026
Examiner Interview Summary
Jul 22, 2026
Applicant Interview (Telephonic)

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Prosecution Projections

3-4
Expected OA Rounds
71%
Grant Probability
99%
With Interview (+35.8%)
2y 9m (~0m remaining)
Median Time to Grant
Moderate
PTA Risk
Based on 760 resolved cases by this examiner. Grant probability derived from career allowance rate.

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